Pope Leo X

Pope Leo X (11 December 1475-1 December 1521), born Giovanni di Lorenzo de Medici, was Pope from 9 March 1513 to 1 December 1521, succeeding Pope Julius II and preceding Pope Adrian VI. During his tenure as Pope, Martin Luther began the Protestant Reformation to challenge the authority of the Pope, and he engaged in a war to secure Urbino for his nephew Lorenzo II de Medici.

Biography
Giovanni di Lorenzo de Medici was a member of the House of Medici of Florence, Italy, and the younger members of the College of Cardinals backed his bid to become Pope upon the death of Pope Julius II, whom he succeeded in 1513. In 1517, he secured his nephew's acquisition of the Duchy of Urbino, but the finances of the Papal States were drained as a result of the war. Some other cardinals attempted to poison him, as he was an unpopular Pope, and he offered to grant indulgences (remission of sins) to those who donated to the reconstruction of St. Peter's Basilica, showing the corruption of the Catholic church. In response, Martin Luther nailed his 95 Theses to the All Saints' Church in Wittenberg, Germany to protest against the Pope, and he died in 1521.